Air-brake.



No. 649,||8. Patented May 8, |900. A. L. WATKINS.

AIR BRAKE.

(Applicgtion med Dm-n 13, 1s9s.)`

(No Model.) -2 Sheets-Sheet I.

m: Nonnls PETERS co. PHQTQLITHQ., WASHINGTON. u a

UNITED STATES PATENT EErcE.

ARTHUR L. VVATKINS, OF BELLEVILLE, ARKANSAS, ASSIGNOR OF ONE-HALF TO LEE BRUTON, OF SAME PLACE, ANI) EARNEST BUOKMAN, OF MAR- VINVILLE, ARKANSAS.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent N o. 649,118, dated May 8, 1900.

Application led December 13, 1898. Serial No. 699,120. (No model.) I

To all whom it may concern:

Be it known that I, ARTHUR L. WATxINs, a citizen of the United States, residing at Belleville, in the county of Yell and State of Arkansas, have invented certain new and useful Improvements in Air-Brakes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which xo it appertains to make and use the same.

In ordinary air-brake devices the brakeactuating cylinders are all operated from the engine, and hence the pipes of the first car must be coupled with devices on the engine I 5 and with pipes on the next carin the rear,

and so on until the last car of the train is included, and obviously a break at any point leaves at least all brakes to the rear of that point inoperative. To avoid all this coupling zo and uncoupling and to provide devices that are not aected by derangements on other cars or on the engine are objects of this invention.

In the drawings, Figure l is a side elevation of one end of a car provided with my devices. Fig. 2 is a diagrammatic plan ot' devices beneath the car. Figs. 3, 4, 5, 6, 7, and 8 are detail views.

In the views, A represents a car, and B the truck beneath its end. Upon one of the axles 3o O is fixed a gear D, meshing with a geared crank-plate E, which, by means of a pitmanl E', operates an ordinary piston air-compressor F for forcing air into a reservoir G through a pipe I-I. The pipe H is provided with a 3 5 safety-valve mechanism consisting of a cylinder I, piston I therein, and centrally-pivoted lever I2, bearing an adjustable counterweight 13 on one arm and having its other arm connected to a sliding valve I4, which when open 4o allows the compressor to discharge into the open air. By this means the air in the reserv voirv is kept at a uniform pressure.

From the reservoir a pipe J leads to a valve device at K, and from this one pipe L passes to a cylinder M for actuating a brake N in the usual way, and another pipe L' leads to the opposite end of the cylinder M, so that air passing through this pipe will positively force the brake from the wheels. Between the devices at K and the cylinder M the pipe L' is divided and a meter O is interposed. This meter consists of a closed chamber provided with a slide-valve O, operated by a centrallypivoted lever P, connected to the piston-rod of the air-compressor, so that the movements of the piston and valve are synchronous, though opposite. The ports of the meter are the mouths of the two parts of the pipe L',

and the length of the valve is such that in oscillating it completely closes the one before it begins to open the other. It follows that no air can pass through the meter unless the piston-rod is in motion-that is, unless the car is moving. This absolutely prevents the positive withdrawal of the brake when the car is stationary, and thereby allows the car to rest securely when left standing upon a grade. The valve devices at K consist of a closed cylindrical casing Q, containing a central hub fixed to an oscillating shaft Q'and provided with three arms Q2 Q2 Q3, having valveplates Q4, the first two adapted to close,respectively,openin gs Q5 in the casing, and the other having an analogous plate to close the inletopening from the pipe J. The arms Q2 allow air to pass them, but the arm Q3 is wider and lits the upper and lower Walls, so that no air can pass. Opposite the pipe J a partition QG extends from the hub to the casing, so that it, together with the hub and the arm Q3, divides the box into two compartments not directly communicating. A crank-arm R is fixed to the shaft Q without the casing. Each compartment has an opening Q5, and the pipe L leads from one and the pipe L from the other. The valves are so arranged with reference to the openings in the casing that if the inlet from J be open the opening Q5 in the compartment to which air is thus admitted Will be closed, while the other will be open. If, for example, air enters the compartment from which the pipe L leads, air will pass through this piperand entering the cylinder will cause the brake to be applied, airv upon the opposite side of the piston in this cylinder passing out at the same time through the pipe L' and the corresponding port Q5. If by shifting the crank R the arm Q3 be thrown to the opposite side of the inlet, the conditions are exactly reversed and the brake is thrown from the wheels. It it be desired to balance the valves, arms Q7 Q7, analogous to Q3, may be added, as shown in the drawings. To the crank R is pivoted a rod S, which is connected with a buffer plate or disk S atv the end of the carand in position to be pressed by some part-for example, the bumper of the next car. It is plain that when this car presses toward the one next in front, if the disk S' be in front or when the carin the rear presses toward this car if the disk be in the rear, the valve mechanism will be turned and the brake will be applied. When pressure on the rod ceases, a spring T returns the rod to normal position, shifts the valve, and throws oi the brake, provided' that the car be in motion, so that air can pass through the meter O and pipe L. Were no other devices used, the 'car could not be backed. The rod S is therefore not connected directly to the buer, but is attached to one end of a centrally-pivoted lever S2. A slot S7 ext'ends nearly from end to end of the lever, and in this slot lies a rod S3, connected to the buder, urged forward by a strong spring S5 and provided with a head S4, which engages the rear face of the lever when the rod is drawn forward at any time, but which leaves the rear face of the lever when the rod is pushed rearward,unless the rod be approximately in alinement with the rod S. In this latter case the head will abut against a web of metal forming part of-the lever and covering the slot at this end, so that the head here lies in a dovetail recess, laterally open, however, so that the rod can slide in the slot toward the levers pivotal axis. Vith the parts in this position, then, pressure upon the buier, if sufiicient to overcome the force of the spring, is transmitted through the rod S3, the web of metal,

and the rod S to the valve-arm, opening the valve and allowing the air through the pipe L to apply the brake. The headed rod is at will swung out of such alinement by means of a rod S6, running to the side of the car. As soon as the head has passed from beneath the web, pressure upon the buffer merely pushes the rod rearward in the open part of the slot and has no effect upon the valve. however, the rod be swung past the pivotal axis of thelever, the spring S5 pulls it forward, and its head engaging the rear face of the lever forces the latter to swing, pushing the rod S rearward and opening the valve. If the car be at rest, the rod S3 being out of aliney ment no bumping of another car nor any other action other than restoring the alinement and starting the car can admit air through the pipe L', and thereby throw off the brake.

It is to be observed that this apparatus does not prevent attaching hand-operated devices to the brakes.

. Since changes in construction maybe made without changing the invention I wish to claim my devices broadly as well as specifically.

What I claim is- 1. The combination with a car-axle and a brake-cylinder of an air-chamber provided with inlet and exit ports for compressed air, a passage leading from the exit-port to one end of the brake-cylinder, an oscillating valve always closing one of said ports, and means whereby rotation of the axle oseillates the valve opening each port in succession after closing the other, whereby air passes through thel chamber to the cylinder only when the axle rotates.

2. The combination with an air-brake cylinder, of a valve arranged to admit air to either end of the cylinder, a longitudinallysliding rod for changing the position of said valve, a centrallypivoted lever having one arm connected to said rod to operate it, a second rod normally alining with the first, sliding along the lever from one arm thereof to the other, and arranged to engage the lever when moved longitudinally in one direction and to engage it when moved in the other direction only when in alinement with the first rod.

3. The combination with the brakecylin der, of the valve controlling the admission of air for forcing the brake into action, the valve operating rod, the centrally-pivoted slotted lever having the recessed end connected to said rod, the headed rod lying in the slot in the lever and normally alining with the first rod, with its head in said recess, the spring tending to draw the second rod from the iirst, and means for swinging the second rod in its slot into and out of alinement with the irst.

4. The combination with a brake-cylinder, of a channel for admitting air for applying the brake, a second channel for admitting air to throw oft the brake positively, means whereby rotation of the axle only, opens the second channel, and means whereby the iirst channel may be automatically held open whenever desired.

5. In valve apparatus for air-brakes, the combination with the chamber divided into non-communicating compartments by a partition consisting in part of a swinging arm, an inlet opening into one or the other of said compartments according to the position of said arm, an exhaust-opening in the wall of each compartment, valves swinging with said arm and in position to close the exhaust-opening in the compartment into which the inlet leads and to open the other, an outlet-pipe leading from each compartment, and means for swinging said arm from side to side.

6. The combination with the car and its axle, of the air-compressor operated by the rotation of the axle, the air-reservoir, the pipe leading from the compressor to the reservoir, the safety-valve devices interposed in said pipe, the valve-chamber, the pipe leading from the reservoir to said chamber, the brake- IOO IIO

IZO

e i v cylinder, the two pipesleading from the chamthe action of said spring and. cause the openber to the ends of the cylinder, respectively, ing of said Valve and application ofthe brake. Io

the meter operated from the axle and con- In testimony whereof I affix my signature trolling the passage of air in one of said pipes, in presence of two witnesses. p

5 a spring normally holding said valve in posi- ARTHUR L. WATKINSL tion to prevent application of the brakes, a Witnesses: buffer at the end of the car, and means where- WALLACE GREENE,

by pressure upon said buffer may overcome HARRY S. ROHRER. 

